const int relay_pin  = 18;
const int button_pin = 32;

void setup() 
{
  Serial.begin(115200);
  pinMode(relay_pin, OUTPUT);
  pinMode(button_pin, INPUT_PULLUP);
}

void loop() 
{
  int value = digitalRead( button_pin);
  if( value == LOW)        // low is pressed
  {
    digitalWrite( relay_pin, HIGH);
  }
  else
  {
    digitalWrite( relay_pin, LOW);
  }

  delay(100);           // slow down the sketch
}